Charge distribution chute

ABSTRACT

The resistance to erosion of a charge distribution chute for use within a blast furnace is improved by a multiplayer construction comprising a channel-defining support member and, mounted thereon, a plurality of overlapping wear-resistant members. The wear-resistant members are themselves of multilayer construction and consist of carrier plates with a layer of abrasion resistant material affixed thereto.

United States Patent Legille et al.

CHARGE DISTRIBUTION CHUTE Inventors: Edouard Legille, Luxembourg; Rene N. Mahr, Howald'Hesperange. both of Luxembourg [73] Assignee:

S.A. des Anciens Etablissements Paul Wurth, Luxembourg 221 Filed:

July 7. 1972 June 27, 1973 Appl. No.: 374,049

Foreign Application Priority Data Luxembourg 65680 References Cited UNITED STATES PATENTS Topp Shallenberger 193/1 138/147 X Mcssiter 193/3 X 1 June 17, 1975 1.523.681 1/1925 Austin 138/140 1.733.573 10/1929 Allen 138/140 1.747.752 2/1930 Brandt 193/4 1.825.678 10/1931 Pittman i i 138/140 2.530.320 11/1950 Abraham 138/140 X 2.731.466 1/1956 Hcffner i i 138/140 X 3.379.219 4/1968 Schuh et a1,..... 138/140 X 3.693.812 9/1972 Mahr et a1. 193/3 X FORElGN PATENTS OR APPLlCATlONS 233.115 4/1910 Germany 138/140 Primary Examiner-Evon C. Blunk Assistant Examiner-James L. Rowland [57] ABSTRACT The resistance to erosion of a charge distribution chute for use within a blast furnace is improved by a multiplayer construction comprising a channeldefining support member and, mounted thereon, a plurality of overlapping wear-resistant members. The wear-resistant members are themselves of multilayer construction and consist of carrier plates with a layer of abrasion resistant material affixed thereto.

2 Claims, 2 Drawing Figures CHARGE DISTRIBUTION CHUTE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to enhancement of the life of members which are subjected to erosion as a result of the movement of solid material thereover. More specifically, this invention is directed to distribution chutes for use in the charging of furnaces, for example blast furnaces, and particularly to wear-resistant coatings for such chutes. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.

2. Description of the Prior Art While not limited thereto in its utility, the present invention is particularly well suited for use in a bell-less charging installation for a shaft furnace. A novel recently introduced and highly successful bell-less charging installation for furnaces is disclosed and claimed in U.S. Pat. No. 3,693,812, assigned to the assignee of the present invention, U.S. Pat. No. 3,693,812 is hereby incorporated herein by reference. The patented device, for the first time, permitted the furnace charge or burden to be supplied in metered quantities from an intermediate storage bin to a vertically oriented central feed spout. In the patented apparatus the charge material is delivered via the central feed spout to a rotary distribution chute which is capable of pitch angle adjustment independently of the rotation thereof; the distribution chute being arranged centrally in the blast furnace throat or port. By means of the exercise of control over the rotary position and angle of inclination of the distribution chute the profile of the charge on the furnace hearth can be controlled to obtain a predetermined configuration commensurate with maximizing the efficiency of furnace operation.

Considering the environment of a blast furnace, the charge material or burden will consist of ore, coke, cinders, etc.; the charge material thus contains hard, sharp-edged materials. Sliding frictional contact between such materials and surfaces of the charging installation impose very severe demands on the thus contacted components of the charging installation. In particular, the distribution chute of a charging installation of the type disclosed in referenced U.S. Pat. No. 3,693,812 is subjected to a very high degree of wear since the charge material exiting from the central feed spout is delivered to the chute and thereafter moves along the chute at the delivery speed and with a change of direction.

The above briefly described wear or erosion resulting from friction between the charge material and the rotary distribution chute necessitates frequent dismantling of the chute for repair or replacement. Because the chute is positioned at the center of the blast furnace port, repair or replacement thereof requires that the furnace be shut down. In addition, the manufacture of distribution chutes of the type disclosed in referenced U.S. Pat. No. 3,693,812 has been a comparatively expensive procedure due to the use of special heatresistant steels and the necessity of forming such mate rials into the proper special shapes.

SUMMARY OF THE INVENTION The present invention overcomes the above briefly discussed disadvantages by providing a novel member with enhanced resistance to wear resulting from sliding contact with irregularly shaped solid materials. Thus, in accordance with the present invention, an improved charge distribution chute for a bell-less shaft furnace charging installation is provided.

A distribution chute in accordance with the present invention has an outer casing of heat-resistant steel and a cladding of wear-resistant material on the surfaces which are contacted by the sliding charge material. A particularly unique feature of the present invention is the formation of the cladding from a plurality of individual wear-resistant members having approximately the same cross-sectional shape as the outer casing. The wear-resistant members which define the cladding are removably attached to the outer casing and are arranged in the manner of scales or shingles so that, in the material flow direction, each lower wear-resistant member projects toward the discharge end of the chute relative to the adjacent upper wear-resistant member.

In a preferred embodiment a distribution chute in accordance with the present invention has the shape of an upwardly open half-pipe through which the charge or burden being delivered into a furnace will pass. Also in the preferred embodiment, the wearresistant members which comprise the cladding are designed so as to be interchangeable with one another.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be better understood and its numerous objects and advantages will become ap parent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the two figures and in which:

FIG. 1 is a side elevation view of a distribution chute in accordance with the present invention; and

FIG. 2 is a cross-sectional front elevation view of the chute of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference simultaneously to FIGS. 1 and 2, a charge distribution chute in accordance with the present invention is indicated generally at 2. The chute 2 includes an outer discharge channel defining member 4 comprised of heat-resistant steel. Channel defining member 4 has, at its upstream end, an impact member 6 which is engaged by shafts 8 and 10. The shafts 8 and 10 serve to mount and retain the distribtuion chute in the drive mechanism therefore. Member 6, being located at the upstream end of the chute, absorbs the impact of charge material exiting a feed spout. Member 6 defines an upstream extension of the open-topped channel defined by member 4 and has higher side walls for engagement by shafts 8 and 10.

The inner or charge contacting portion of chute 2 is defined by a plurality of wear-resistant members which present exposed surfaces of abrasion-proof material. The wear resistant members each comprise a carrier plate, for example plates 12 and 16, formed from thick walled heat-resistant steel sheeting. Layers l4 and 18 of non-abrasive hard material are welded to respective carrier plates 12 and 16. The multilayer wear-resistant members are assembled so as to overlap one another in scale-like manner so that at any point along the chute 2 at least two wear-resistant members are superimposed and the lower wear-resistant member projects, relative to the upper wear-resistant member, in the downstream or material flow direction. This overlap- 3 ping relationship may most clearly be seen from FIG. 1.

The channel defining member 4 is provided, along its oppositely disposed upper edges, with apertures such as holes 20, and 20". Member 6 is also provided with similar holes. The individual wear resistant members, such as member 12-14 and 16-18, are detachably connected to channel defining members 4 and 6 by means of bolts or other suitable fasteners which pass through holes 20.

The wear-resistant members will all have approxi mately the same shape and thickness so that such members may be interchangeable with one another. As a result of this manner of construction only a limited number of replacement wear-resistant members are necessary and the replacement process is greatly facilitated. Only the terminal wear-resistant members, indicated at 22 and 24, are shorter than the remaining members in order that such terminal members do not project beyond the ends respectively of channel defining members 4 and 6.

When a single damaged wear-resistant member is to be replaced the connections between the channel defining member and the two wear-resistant members immediately above the damaged member are loosened thereby permitting the two upstream members to be slightly raised. The damaged wear-resistant member can then be removed and replaced.

The carrier plates, such as plates 12 and 16, are rarely damaged in the present invention. Thus, when an abrasion-resistant layer becomes worn, the carrier plates may be reused by repair or replacement of the abrasive-resistant layer.

While a preferred embodiment has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.

What is claimed is: l. A charge distribution chute for use within a blast furnace comprising:

a rigid elongated support channel defining body comprised of heat resistant steel; and a plurality of wear-resistant members rigidly affixed to and detachable from the interior channel defin ing surface of said body, said wear-resistant members being individually affixed in overlapping relationship to said body only adjacent their respective upstream ends in the direction of charge material flow of said members, said wear-resistant members each including at least a first carrier plate comprised of heat-resistant steel and a layer of abrasion-resistant material affixed to the carrier plate on the material contacting side of the wearresistant member, said wear-resistant members being shaped to define a channel at least partly commensurate in shape with the channel defined by said body whereby material flowing along the chute will be contained by and in contact with said wear-resistant members to a preselected depth, at least two of said wear-resistant members being superimposed at all points along the channel defining body located downstream of the wear-resistant member positioned at the material receiving upstream end of the chute. 2. The apparatus of claim 1 wherein said layer of abrasion-resistant material of each wear-resistant mem her is welded to the carrier plate. 

1. A charge distribution chute for use within a blast furnace comprising: a rigid elongated support channel defining body comprised of heat resistant steel; and a plurality of wear-resistant members rigidly affixed to and detachable from the interior channel defining surface of said body, said wear-resistant members being individually affixed in overlapping relationship to said body only adjacent their respective upstream ends in the direction of charge material flow of said members, said wear-resistant members each including at least a first carrier plate comprised of heatresistant steel and a layer of abrasion-resistant material affixed to the carrier plate on the material contacting side of the wear-resistant member, said wear-resistant members being shaped to define a channel at least partly commensurate in shape with the channel defined by said body whereby material flowing along the chute will be contained by and in contact with said wear-resistant members to a preselected depth, at least two of said wear-resistant members being superimposed at all points along the channel defining body located downstream of the wear-resistant member positioned at the material receiving upstream end of the chute.
 2. The apparatus of claim 1 wherein said layer of abrasion-resistant material of each wear-resistant member is welded to the carrier plate. 